As the weather is cooling off, you are probably wondering about how you’ll prepare your heating and cooling. After all, HVAC expenses frequently make up a large portion of your monthly electric bill. To figure out new ways to lower their HVAC bill, some owners look closely at their thermostat. Is there a setting they should use to increase efficiency?
Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what does the fan setting offer for the HVAC system? This guide can help. We’ll walk through just what the fan setting is and whether you can use it to cut costs over the summer or winter.
What Is the Fan Setting on My Thermostat?
For most thermostats, the fan setting signifies that the HVAC blower fan remains on. Some furnaces may continue to run at a low level in this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will start the fan through a heating or cooling cycle and shut it off after the cycle is over.
There are advantages and disadvantages to trying the fan setting on your thermostat, and what's ideal can depend on your unique comfort preferences.
Advantages to trying the Fan/On setting:
- You can keep the temperature in each room more uniform by permitting the fan to keep circulating air.
- Indoor air quality can increase since continuous airflow will keep forcing airborne particles into the air filter.
- Fewer start-stop cycles for the blower fan helps expand its life span. Since the air handler is usually a component of the furnace, this means you can prevent the need for furnace repair.
Downsides to switching to the Fan/On setting:
- A continuous fan will likely increase your energy bills by a small margin.
- Nonstop airflow may clog your air filter soon, increasing the frequency you should replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
During the summer, warm air will sometimes persist in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system can pull this warm air into the rest of your home, pushing the HVAC system to work more to keep up with the set temperature. In serious heat, this could lead to needing AC repair more regularly as wear and tear gets worse.
The reverse can occur over the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Keeping the fan on may pump more cold air upward, increasing the amount of heating you need to remain warm.
If you’re still trying to decide if you should try the fan/on setting, don’t forget that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might be best for you if:
Someone in your household suffers from allergies. Allergies and similar respiratory conditions can be hard on the family. Leaving the fan on should help to increase indoor air quality, helping your family breathe easier.
Your home has hot and cold spots. All kinds of homes wrestle with stubborn hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting can help lessen these changes by constantly refreshing each room’s airflow.